Use a custom trace! macro in resolution

[alexcrichton]

Apparently not actually emitting the calls to trace! saves a good deal of stack
space, fixing the overflow found in #1875.

Closes #1875

[rust-highfive]

r? @huonw

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[huonw]

@bors r+

This seems somewhat unfortunate, but I guess it makes sense.

[bors]

📌 Commit 0f3caf9 has been approved by huonw

[bors]

⌛️ Testing commit 0f3caf9 with merge e943040...

[bors]

💔 Test failed - cargo-win-gnu-64

[alexcrichton]

@bors: retry

On Mon, Aug 10, 2015 at 5:29 PM, bors notifications@github.com wrote:

[image: 💔] Test failed - cargo-win-gnu-64
http://buildbot.rust-lang.org/builders/cargo-win-gnu-64/builds/119

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Reply to this email directly or view it on GitHub
#1887 (comment).

[bors]

⚡️ Previous build results for cargo-linux-64, cargo-win-msvc-64 are reusable. Rebuilding only cargo-linux-32, cargo-mac-32, cargo-mac-64, cargo-win-gnu-32, cargo-win-gnu-64, cargo-win-msvc-32...

[bors]

☀️ Test successful - cargo-linux-32, cargo-linux-64, cargo-mac-32, cargo-mac-64, cargo-win-gnu-32, cargo-win-gnu-64, cargo-win-msvc-32, cargo-win-msvc-64